Extensible connector for conductors rails

ABSTRACT

The invention relates to a connector for connecting two conductor rail sections ( 2   a   , 2   b ). Said connector comprises at least one electrical conductor ( 1 ), the ends ( 1   a   , 1   b ) thereof being respectively connected to a conductor rail section ( 2   a   , 2   b ) in a conductive and fixed manner, and a connection element ( 4 ) which interconnects the ends ( 2   a′   , 2   b ′) of the mutually facing conductor rail sections ( 2   a   , 2   b ). The connection element ( 4 ) is positioned in a displaceable or sliding manner in or on both ends ( 2   a′   , 2   b ′) of the mutually facing conductor rail sections ( 2   a   , 2   b ) and the electrical conductor ( 1 ) is fixed to the connection element ( 4 ).

[0001] The present invention relates to a connector for connecting two conductor rail sections, the connector having at least one electrical conductor and one of its respective ends being connected in a conductive manner to a respective conductor rail section, the connector having a connection element which connects the facing ends of the conductor rail sections to one another.

[0002] Generic conductor rail connectors are also frequently called extensible connectors, these connectors compensating a length change in the conductor rail sections owing to temperature influences and conducting the electrical current from one conductor rail section to the next.

[0003] The electrical conductor of generic connectors is designed either flexibly or rigidly, the electrical conductor in the rigid configuration thereof having to be formed in such a way that in the event of length changes of the conductor rail sections, the electrical conductor can be deformed and its length thus changed. If large electrical currents have to be transmitted from one conductor rail section to the next, relatively large cross-sections of the electrical conductor of the connector are required. As the flexibility of an electrical conductor decreases with the cross-section, a plurality of electrical conductors, for example flexible copper strands or copper cables, are frequently used for large current intensities for electrical current transmission. These cables lie outside the conductor rail and therefore need addition space. Owing to the fact that the connectors are fastened on the side of the conductor rail sections remote from the sliding face, the ends of the conductor rail sections cannot be fastened to a carrier or other parts by means of fastening elements, so they can swing freely. As already explained, the electrical conductor is to be designed with a large cross-section so large electrical currents can be transmitted. This produces the problem that relatively high pressure forces occur to change the air gap between the ends of the conductor rail sections owing to temperature variations, so the conductor rail suspensions are subject to large loadings.

[0004] Owing to the pressing force of a current collector, the conductor rail section, in particular the freely swinging ends thereof, are moved out of their normal position so the adjoining ends of the conductor rail sections no longer adjoin in an impact-free manner and therefore the current collector can be permanently damaged when the ends of the conductor rail sections are traversed.

[0005] It is the object of the present invention to provide a connector or extensible connector for conductor rail sections which ensures that the conductor rail ends adjoin in an impact-free manner and which has relatively small dimensions even with high current intensities.

[0006] This object is achieved according to the invention with a connector with the features of claim 1. Further advantageous configurations of this connector according to the invention are produced by the features of the sub-claims.

[0007] The connector or extensible connector according to the invention serves to compensate the length change in the conductor rail sections between defined fixed points. It combines both the electrical current transmission from conductor rail section to conductor rail section and the mechanical guiding of the conductor rail section ends, in order to achieve impact-free transition at the air gap in the region of the sliding faces of the conductor rail sections.

[0008] For this purpose, the connection element is advantageously mounted in a displaceable or sliding manner at the ends of the conductor rail sections. The ends of the conductor rail sections are advantageously always aligned with respect to one another by the connection element. Owing to the sliding or displaceable mounting of the connection element at the facing ends of adjacent conductor rail sections, the ends of the conductor rail sections can move towards or away from one another owing to thermal expansion or thermal contraction, wherein they are always held in position with respect to one another by the connection element.

[0009] Since the electrical conductor is fastened to the connection element, the connection element always remains in the region of the ends of the two conductor rail sections and requires no additional fastening. The connection element, for improved mounting, advantageously has a bearing part made of wear-resistant plastics material, by means of which a low coefficient of friction is produced between the connection element and conductor rail section. It is also advantageous if the electrical conductor consists of a parcel of joined, flexible, lamellar strips. The required size of the cross-section can therefore be adapted to the respective current loading capacity without the outer overall size being substantially influenced. The individual lamellar strips or foils are pressure welded at the contact points and copper clad aluminium sheets are placed underneath owing to the contact corrosion.

[0010] The electrical conductor, which is in particular a Cu lamellar strip is advantageously constructed in such a way that the total extension path is divided into two partial extension paths. The mechanical stress in the movable partial region of the electric conductor is therefore sharply reduced. Since the electrical conductor is fastened to the connection element, in particular screwed on, a further improvement in the flexural strength of the total connector is produced. The partial extension paths are advantageously produced by an undulating shaping of the electrical conductor. However, it is also possible to provide a saw tooth-shaped shaping of the electrical conductor or to lay it in loops. Owing to the special undulating design, a reduction in the pressure force required to change the air gap between the ends of the conductor rail sections is advantageously produced, whereby the load on the conductor rail attachments is advantageously reduced.

[0011] It is also advantageous if the width of the electrical conductor or of the Cu lamellar strip is smaller relative to the opening of the C-profile of the conductor rail sections in the case of conductor rail sections which are C-shaped in cross-section, so that the in particular undulating shaping or the inner half-wave can submerge into the C-profile when the ends of the conductor rail sections are pushed together, so a small overall height can advantageously be achieved over the total extension region of the connector.

[0012] A possible embodiment of the connector according to the invention is described in more detail hereinafter with the aid of the drawings, in which:

[0013]FIG. 1 shows conductor rail sections connected by a connector according to the invention;

[0014]FIG. 2 shows an arrangement according to FIG. 1 with ends of the conductor rail sections approaching one another owing to thermal change in length; and

[0015]FIG. 3 shows a cross-sectional view through an arrangement according to FIG. 1.

[0016]FIG. 1 shows two conductor rail sections 2 a and 2 b, the ends 2 a′ and 2 b′ of which are spaced apart from one another. The conductor rail sections 2 a and 2 b each have an upwardly pointing sliding face S in FIGS. 1 to 3. The current rail sections are electrically connected via the connector according to the invention. The current rail sections consist of an aluminium profile, the cross-section of which is substantially C-shaped (FIG. 3). The electrical conductor 1 serves for the conveyance of current from one conductor rail section to the other. For this purpose, fastening means 3 a and 3 b are provided on the conductor rail sections 2 a and 2 b, one respective end 1 a or 1 b of the electric conductor 1 being fastened in a conductive manner to a fastening means 3 a or 3 b by means of fastening screws 6. The fastening means 3 a and 3 b are rigidly fastened by means of fastening screws 3 a′ and 3 b′ to each conductor rail section 2 a and 2 b. Arranged in the region of the ends 2 a′ and 2 b′ of the conductor rail sections 2 a and 2 b is a connection element 4 which is mounted in a displaceable and sliding manner in the conductor rail sections 2 a and 2 b designed as profile bodies. The central region 1 c of the electrical conductor 1 is fastened by means of fastening screws 5 to the connection element 4. The connection element 4 and electrical conductor 1 mutually reinforce one another thereby, so the total system receives a higher rigidity.

[0017] The mounting of the connection element 4 in the ends of the conductor rail sections 2 a and 2 b takes place in the direction of the longitudinal extent of the conductor rail sections 2 a and 2 b so the ends 2 a′ and 2 b′ of the conductor rail sections 2 a and 2 b can approach one another (FIG. 2) or distance themselves from one another owing to temperature length changes. The ends 2 a′ and 2 b′ of the conductor rail section 2 a and 2 b are guided by the connection element 4, so the sliding faces S always lie in an impact-free manner in one plane. The electric conductor 1 is always shaped in an undulating manner between the connection pieces 3 a and 3 b and the connection element 4, so a change in length of the conductor rail sections 2 a and 2 b can be compensated by these region 1 d and 1 e of the electrical conductor 1.

[0018] As shown in FIGS. 1 and 2, the shaping of the regions 1 d and 1 e is such that it consists of two smaller half-waves and a central larger half-wave, the central larger half-wave pointing in the direction of the conductor rail sections 2 a and 2 b. If the conductor rail sections 2 a and 2 b move the fastening elements 3 a and 3 b towards one another owing to the thermal length change, a length compensation may take place owing to the regions 1 d and 1 e, the central half-waves engaging or immersing in the lower opening of the C-shaped profile of the conductor sections owing to their configuration. For this purpose, the width B of the electrical conductor which is manufactured in particular as a Cu lamellar strip, is smaller than the spacing of the collar-shaped projections 2 a″ of the respective conductor rail section serving to guide the connection element, so a smaller overall height of the total arrangement is achieved.

[0019] As shown in FIG. 3, the connection element 4 consists of two plate-shaped parts 4 b and 4 c and a bearing part 4 a arranged therebetween which, on its elongate flat sides, has longitudinal grooves 4 a″ in which the projections 2 a″ engage.

[0020] A plurality of screws 5 with their shaft 5 a penetrates the region 1 c of the electrical conductor 1, the plate-shaped parts 4 b and 4 c and the bearing part 4 a. For this purpose, the electrical conductor 1, the plates 4 b and 4 c and the bearing part 4 a have corresponding through-holes 1 c′, 4 a′, 4 b′ and 4 c′. The screw 5, at its shaft end, has an external thread 5 b which corresponds to an internal thread 4 c″ of the plate 4 c. By tightening the screws 5, the parts penetrated by the screw 5 are pressed together by means of their screw head and the plate 4 c and held together permanently. The longitudinal grooves 4 a″ are not thus influenced in their fit.

[0021] To assemble the arrangement, the conductor rail sections 2 a and 2 b are assembled one after the other on holders, not shown, by means of insulators. As at least the connection element 4 with its bearing part 4 a has to be pushed from the end face of the conductor rail section profile onto the projections 2 a″, at least the connection element 4 has to be pushed in advance prior to the assembly of the second conductor rail section onto the conductor rail section still to be assembled or already assembled. To allow a subsequent assembly of the connector when the conductor rail sections are already assembled, it is possible for the bearing part 4 a to consist of two parts, the two parts then also being held together by the screws 5.

[0022] It is obviously possible for the fastening elements 3 a and 3 b to be designed in their basic structure similar to the construction of the connection element 4, the bearing part 4 a which in particular in the connection element 4 is manufactured from plastics material, then being replaced by a constructionally identical part, but made of a conductive material, so a transition resistance which is as small as possible is produced between the conductor rail section and the electrical conductor.

[0023] In a further embodiment, not shown, the connection element can be rigidly mounted on one end of a first conductor rail section, in particular screwed on, wherein it is mounted in a displaceable or sliding manner in the end of the other conductor rail section. In this embodiment, the connection element can be designed in such a way that the rigidly mounted part of the connection element transmits the electrical current from the electrical conductor to the conductor rail section. In this embodiment, only one fastening means 3 a or 3 b is advantageously required which is fastened to the second conductor rail section. However, there is no division here of the extension path into two partial extension paths which are spatially separated from one another by the connection element. The shapings of the electrical conductor have to be adapted in the process according to requirements. In order to achieve stability which is as high as possible with simultaneously small overall height, the electrical conductor in this embodiment is also fastened to the region of the connection element which is mounted in a sliding or displaceable manner on the second conductor rail section. A higher rigidity of the region of the electrical conductor located between the connection element and the fastening means can thus be achieved. 

1. Connector for connecting two conductor rail sections (2 a, 2 b), the connector having at least one electrical conductor (1), and its ends (1 a, 1 b) being connected to a respective conductor rail section (2 a, 2 b) in a conductive and fixed manner, the connector having a connection element (4) connecting the facing ends (2 a′, 2 b′) of the conductor rail sections (2 a, 2 b) to one another, characterised in that the connection element (4) is mounted in a displaceable or sliding manner in or on the two mutually facing ends (2 a′, 2 b′) of the conductor rail sections (2 a, 2 b), and the electrical conductor (1) is fastened to the connection elements (4).
 2. Connector according to claim 1, characterised in that the central region (1 c) of the electrical conductor (1) is fastened to the connection elements (4).
 3. Connector according to claim 1, characterised in that the connection element (4) holds the conductor rail sections (2 a, 2 b) in position in such a way that the sliding faces (S) of the conductor rail sections (2 a, 2 b) adjoin in an impact-free manner.
 4. Connector according to claim 1, characterised in that the connection element (4) has a bearing part (4 a) which is manufactured, in particular, from a wear-resistant material, in particular plastics material.
 5. Connector according to claim 4, characterised in that the bearing part (4 a) has grooves (4 a″) extending in the longitudinal direction of the connection element (4), which grooves (4 a″) serve as a guide profile and in which grooves in particular collar-shaped projections (2 a″, 2 b″) of the conductor rail sections (2 a, 2 b) engage.
 6. Connector according to claim 4, characterised in that the bearing part (4 a) is arranged between two plate-shaped parts (4 b, 4 c) manufactured in particular from an electrically conductive material, the electrical conductor (1) resting with its central region (1 c) on the side of the one plate-shaped part (4 b) remote from the conductor rail section.
 7. Connector according to claim 6, characterised in that the parts (4 b, 4 c), the bearing part (4 a) and the conductor (1) are held together or pressed against one another by means of at least one fastening screw (5).
 8. Connector according to claim 7, characterised in that the fastening screw (5) penetrates the parts (4 b, 4 c), the bearing part (4 a) and the conductor (1), the part (4 c) having a hole with an internal thread (4 c′) which corresponds to the external thread (5 b) of the fastening screw (5).
 9. Connector according to claim 1, characterised in that the electrical conductor (1) has at least one shaping (1 d, 1 e) for changing the length of the connector, the shaping stretching or extending transverse to the longitudinal extent of the conductor (1).
 10. Connector according to claim 9, characterised in that the shaping (1 d, 1 e) is undulating or zigzag shaped in design.
 11. Connector according to claim 9, characterised in that the shaping (1 d, 1 e) is designed in such a way that this region of the conductor can be compressed or stretched in its length in the manner of an accordion.
 12. Connector according to claim 9, characterised in that the shaping consists of two respective small half-waves and a larger half-wave arranged therebetween, the larger half-wave pointing with its wave peak in the direction of a conductor rail section (2 a, 2 b).
 13. Connector according to claim 9, characterised in that at least one respective shaping is arranged between the central region (1 c), which is fastened to the connection element (4), and a respective end (1 a, 1 b) of the electrical conductor (1).
 14. Connector according to claim 1, characterised in that the electrical conductor (1) is formed from stacked foil sheets.
 15. Connector according to claim 14, characterised in that the foil sheets are pressure welded to one another and copper clad aluminium sheets are placed underneath.
 16. Connector according to claim 9, characterised in that the width (B) of the electrical conductor (1) is such that the conductor (1) can engage, at least with parts of its shapings (1 d, 1 e), in recesses of the conductor rail sections.
 17. Connector according to claim 9, characterised in that the width (B) of the electrical conductor (1) is smaller than the spacing of the narrow end faces of the projections (2 a″) from one another. 